They usually have weight ranges. Some are zippered, some have buckles, and some have both.
My 1 yr old has an infant life vest for kayaking.
My 2 & 4 yr old have youth vests which we also use for kayaking.
I would say as snug as possible without hurting... Cause if they're not, they might ride up into the child's face and be uncomfortable. 1yr old's has a strap that goes between the legs.
My 2 & 4 yr old also have water wings. My 1 yr old is probably too young for that. They also sell some with the wings and a float that goes across the child's chest.
If you can, try the vests on in the store.
Also, probably goes without saying, but still definitely need to keep littles within arms reach because they could end up stuck face down.
Sent from my LGLS996 using Tapatalk